From the product description, check product page for current description, price and availability:

• Made in Germany of a very high quality fiber plastic. Extremely Durable
• We have tested them and they showed no signs of wear after repeated tightening and Un-tightening of regulator to CO2 bottles
• Includes pin that allows you to attach to regulator so they won’t fall off when changing out cylinders
• Affordable product that allows you to leave it on your regulator permanently!
• Fits Standard American Beer Regulators

• The Most Difficult Spot to Check for CO2 Leaks
• Keg O-Ring Materials Selection! – EPDM, Silicone and Buna-N?
• Why Do I Have Bubbles in My Beer Line? Diagnosing and Fixing Kegerator Foam Problems
• Five Benefits of Using Corny Kegs As Fermenters
• Rebuilding & Reconditioning Homebrew Kegs!
• Food Safe Replacement Keg O-Rings in Bulk
• Hands on Review: Kegland DuoTight Fittings & EVABarrier Tubing!
• Why Won’t My Homebrew Keg Carbonate? Fixing Draft Beer Carbonation Problems
• What Does a Flow Control Faucet Do?
• Upgrade Your Kegerator – 6 Improvements!
• Serve Homebrew on Any Kegerator & Convert Commercial Kegerator to Homebrew
• Tips and Gear for Growler Filling
• What’s the Difference Between Ball Lock Kegs and Pin Lock Kegs?
• Checking for Draft System CO2 Leaks – Using The Pressure Gauge Method
• Tip: Consider Oetiker Stepless Clamps for Kegerator Gas and Beer Lines
• Hands On Review: Inkbird ITC-308 Dual Stage Temperature Controller +WiFi Version
• Universal Poppets Tips and Tricks!
• Convert Your Mark II Keg & Carboy Washer to a Recirculating Draft Line Cleaning Pump!
• Step by Step: Finding and Fixing Keg CO2 Leaks
• Kegerator Beer Line Temperatures & Reducing Foam with a Recirculating Fan
• Kegging CO2 Use Estimations and Calculations
• Step by Step: Balancing Your Kegerator Draft System
• Building a Simple Ball Lock Draft Line Flushing Setup
• Build a Recirculating Draft Line Cleaning Pump
• Home Brew Keg Roundup – New & Used, 5 and 2.5 Gallon & More!
• Damp Kegerator? Fix Kegerator Condensation
• Portable Draft Beer Serving Options!
• Homebrew Temp Controller Roundup! – Kegerator and Fermentation – concepts, applications and models
• Bulk Keg Orings and Keg Repair Part Numbers